1994 Ford Ranger Starting Problems
I am having intermittent issues with my truck starting. Let me explain.
I purchased this truck as my first vehicle and had to replace the fuel tank because it had a small leak. My neighbor (who used to be a mechanic) dropped the tank and installed the new tank with the old (but still good) sending unit assembly/fuel pump and then re-secured the tank and fuel lines like they were before.
Everything was fine until the fuel line started popping off. (I think that the plastic clip that holds it on the sending unit was broken off when we were working down there.) Anyways, we eventually fixed the line, and it has not since come off of the sending unit. The truck was running well until I went to start it the other morning, and it did not start. When I turned the key, the engine turned over and cranked but did not catch and start. I told my neighbor of the problem and then left for work.
My neighbor thought the issue was a bad fuel pump relay, since the truck started right up when he switched around the relays in the distribution box. To fix the problem, I bought a new relay and put it in the distribution box. The truck then started up just like it should. Yesterday morning, I went to start it, and it would not start on the first try but then caught and started on the second. I drove it to work without any issues.
Yesterday evening, I drove the truck to Wal-mart, parked, and then went inside. When I came back out, the truck wouldn't start. I opened up the distribution box, switched the relays around, and the truck started up. I drove home and thought everything was fine until later yesterday evening when I drove over to my neighbor's house (which is right across the street from me). After parking the truck for ten or fifteen minutes, I could not get the truck to start, and this time, no amount of switching the relays could get it to start.
We have ruled out the following:
1) Spark plugs, since my neighbor connected his tool to the plugs and saw that we were getting plenty of spark; plus, I just replaced the plugs and wires, so I know they're good.
2) Lack of fuel in the tank, since I had between a quarter and half a tank when I stopped at my neighbor's house; he also added more just in case I was out.
3) Leaks in the fuel line, since there was no smell of gas and no evidence of leaking.
The evidence points to the following possibilities as the source of the problem:
1) Fuel pump, since we were getting very little fuel delivered to the engine (not enough to start), there was no fuel pressure in the system, and we did not hear the electronic "hum" usually audible when the key is turned.
2) Wiring harness/wires on top of sending unit, since it/they may be worn out, etc.
3) Fuel pump inertia switch, since I have read a fair amount about Ranger owners having issues with starting their trucks. Some of these people have found that the inertia switch was at fault. I have not checked this yet and do not know if it has been tripped, but this will be the first thing to check when I get home.
4) Wiring harness/wires behind fuse box on driver's side under dash, since I have also read that people have found that these components can wear down and become faulty.
5) Various relays in the distribution box
6) Random modules/switches/relays somewhere in the engine compartment
I would really appreciate any help at all on this matter since my neighbor is somewhat baffled as to why this is happening. I desperately want my Ranger to be running properly and don't want to put down the big bucks if it's a simple fix. Please let me know what you guys think.
Thank you for your time.
1994 Ford Ranger XLT
2.3L 4-cylinder 5-speed
Regular cab w/ long bed
158,xxx miles when purchased